Locking compasses.



No. 732,106. PATENTED JUNE 30, 1903, F. J. lMOGABE.

LOCKING COMPASSES.

APPLIOATIoN 111.2110016. 1902.

N0 MODEL.

' INVENTOR. JM .6%0//0 Y WITNESSES.

Patented June 30, 1903.

OFFICE.

FRANK J. MCCABE, OF SHELTON, CONNECTICUT.

LOCKING COMPASSES.

SPECIFICATION forming part of Letters Patent N o. 732,106, dated June 30, 1903. Application iiled October 6,1902. Serial No. 126,072. (No model.)

To a/ZZ whom, t may concern;

Be it known that I, FRANK J'. MCCABE, a citizen of the United States, residing at Shelton, county of Fairlield, State of Connecticut, have invented new and useful Locking Com` passes, of which the following is a specification.

My invention has for its object to provide locking compasses or dividers which shall be compact and attractive in design, inexpensive to make, and Whose legs shall be capable of being locked at any angle less than one hundred and eighty degrees. It is of course well understood that it is practically essential in many kinds of compasses and dividers used by architects, carpenters, and draftsmen generally that the legs be adapted to be securely locked at any angle at Which it may be required to set them for work; otherwise the user is put to serious inconvenience and loss of time, and it is almost impossible to prevent more or less inaccuracy in the work. Various applications of setscrews have been used, none of which, however, have fully met the requirements of the different uses to which Compasses are likely to be placed by artisans generally, more especially in measuring great angles, the best instruments heretofore produced for this purpose having been Compasses one leg of which Vwas provided with a curved arm passing through the other leg. The clumsiness of this instrument, however, has been an objection, and a still more serious one has been found in the fact that unless the arm was made inconveniently long it was impossible to lock the legs when set at a great angle.

In order to overcome the various objections heretofore found in instruments of this character and to provide locking Compasses that plane ofthe instrument, which just receives` the disk, the pivot 14 passing through leg 11 and centrally through the disk, which lies in the slot, as indicated in the drawings. In practice the disk may be formed integral with leg 10 or, if preferred, may be formed separate and rigidly secured thereto.

16 denotes aset-screw, preferably provided withawinged head 17 for convenience in operation. This set-screw passes through one side of the upperend of leg 11 and is adapted to engage the face of disk 12 to lock the legs at any angle at which it may be desired to set them. Itisobviousthatthelegsmaybelocked at a great angle, as well as a small one, and thatit is practicable to use the instrument with the legs set at an angle of approximately one hundred and eighty degrees.

The operation of my novel Compasses is so simple that it will be clearly understood from the specification, and further description will hardly be required. It is sufficient vto say that if the legs are locked they may be released by giving the set-screw a slight turn backward, and when the legs have been set at any required angle or in the closed position they may be locked there by giving the set-screw a slight turn forward.

Having thus described my invention, I claim- 1. Compasses, one leg of which is provided at its pivot end with a disk and the other leg at its pivot end with a slot to receive the disk and a set-screw passing through. one side of the slotted leg and engaging the face of the disk to lock the legs at any required angle, the legs being free to be opened to one hundred and eighty degrees.

2. In compasses, the combination with a leg having a disk 12 at its pivot end and a leg having a slot at its pivot end adapted to receive the disk, of a pivot whereby the legs are secured together, and a set-screw passing through one side of the slotted leg and en gaging the face of the disk, the legs being free l said set-sorewbeinglocated between the pivot io to be opened to one hundred and eighty degrees.l

3. Compasses., one leg of Which is provided at its pivot end with a disk and the Vother leg at its pivot end with a. slot to receive the disk and a, set-screw passing through one side of the slotted ieg and engaging lthe face of the disk to lock the legs at any required angle,

and the pointed end of the ieg in which it is mounted.

In testimony whereof I affix my signature in presence of two Witnesses.

- FRANK J. MCCABE. W'iinesses:

A. M. WoosTER, S. W. ATHERTON. 

